In investigating the sanitation of freeze-dried foods, two pathways are being followed. The first is concerned with the antimicrobial mechanisms of compounds that would be used in connection with freeze-dried foods in the development of intermediate moisture foods. Consequently, the antimicrobial activity of humectants such as glycerol are being determined, employing Staphylococcus aureus and Bacillus subtilis as test organisms. The second pathway of research is concentrating on the mechanisms by freezing and freeze-drying per se induce injury to Salmonella typhimurium LT2.